| // Copyright 2020 The Pigweed Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| // use this file except in compliance with the License. You may obtain a copy of |
| // the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| // License for the specific language governing permissions and limitations under |
| // the License. |
| |
| #include "pw_checksum/ccitt_crc16.h" |
| |
| #include <string_view> |
| |
| #include "gtest/gtest.h" |
| |
| namespace pw::checksum { |
| namespace { |
| |
| // The expected CRC16 values were calculated using |
| // |
| // http://www.sunshine2k.de/coding/javascript/crc/crc_js.html |
| // |
| // with polynomial 0x1021, initial value 0xFFFF. |
| constexpr uint8_t kBytes[] = {1, 2, 3, 4, 5, 6, 7, 8, 9}; |
| constexpr uint16_t kBufferCrc = 0x3B0A; |
| |
| constexpr std::string_view kString = |
| "In the beginning the Universe was created. This has made a lot of " |
| "people very angry and been widely regarded as a bad move."; |
| constexpr uint16_t kStringCrc = 0xC184; |
| |
| TEST(Crc16, Empty) { |
| EXPECT_EQ(CcittCrc16(std::span<std::byte>()), kCcittCrc16DefaultInitialValue); |
| } |
| |
| TEST(Crc16, ByteByByte) { |
| uint16_t crc = kCcittCrc16DefaultInitialValue; |
| for (size_t i = 0; i < sizeof(kBytes); i++) { |
| crc = CcittCrc16(std::byte{kBytes[i]}, crc); |
| } |
| EXPECT_EQ(crc, kBufferCrc); |
| } |
| |
| TEST(Crc16, Buffer) { |
| EXPECT_EQ(CcittCrc16(std::as_bytes(std::span(kBytes))), kBufferCrc); |
| } |
| |
| TEST(Crc16, String) { |
| EXPECT_EQ(CcittCrc16(std::as_bytes(std::span(kString))), kStringCrc); |
| } |
| |
| extern "C" uint16_t CallChecksumCcittCrc16(const void* data, size_t size_bytes); |
| |
| TEST(Crc16FromC, Buffer) { |
| EXPECT_EQ(CallChecksumCcittCrc16(kBytes, sizeof(kBytes)), kBufferCrc); |
| } |
| |
| TEST(Crc16FromC, String) { |
| EXPECT_EQ(CallChecksumCcittCrc16(kString.data(), kString.size()), kStringCrc); |
| } |
| |
| } // namespace |
| } // namespace pw::checksum |